The following patents have been noted as having some relevance in the present field
U.S. Pat. No. 5,042,395 (Wackerle) issued Aug. 27, 1991 discloses a rail vehicle formed from molded upper section defining the side walls and roof connected to a floor section. The connection is provided by a corner piece which is bonded into an edge piece at each edge of each molded composite panel. The composite panels are formed from exterior sheets with a honey comb core between.
U.S. Pat. No. 6,375,249 (Stanton) issued Apr. 23, 2002 discloses a body structure of a mass transit vehicle where a sandwich floor panel is applied over a vehicle frame including transverse rails and side rails and is attached to the side rails.
PCT published Application 2007/056840 (Stanton et al) published May 24, 2007 discloses a vehicle construction using sandwich panels for the floor, sidewalls and roof where a number of different joint connections are shown.
U.S. Pat. No. 5,403,062 (Sjostedt) issued Apr. 4, 1995 discloses an adhesive panel joint where a tongue portion along one panel edge engages into a channel along a panel edge of a second panel where the side walls of the tongue and channel are slightly tapered.